\newproblem{lay:2_3_18}{
  % Problem identification
	\begin{large}
	  \hspace{\fill}\newline
    \textbf{Lay, 2.3.18}
	\end{large}
	\\
  \ifthenelse{\boolean{identifyAuthor}}{\textit{Ana Peña Gil, Jan. 19th 2014} \\}{}

  % Problem statement
  Can a square matrix with two identical columns be invertible? Why or why not? \\
}{
  % Solution
	When the 2x2 matrix has identical columns, we say their columns are linearly dependent, so its determinant is zero. Because of that, the matrix is not invertible. \\
}
\useproblem{lay:2_3_18}
\ifthenelse{\boolean{eachProblemInOnePage}}{\newpage}{}
